<h4>Tool</h4><table border="0"><tr><td valign="top"><b>Name</b></td><td valign="top">Vegetation Index (Slope Based)</td></tr><tr><td valign="top"><b>ID</b></td><td valign="top">1</td></tr><tr><td valign="top"><b>Author</b></td><td valign="top">V.Olaya (c) 2004, O.Conrad (c) 2011</td></tr><tr><td valign="top"><b>Specification</b></td><td valign="top">grid</td></tr></table><hr><h4>Description</h4>Slope based vegetation indices.

<ul><li>Difference Vegetation Index
    DVI = NIR - R</li>
<li>Normalized Difference Vegetation Index (Rouse et al. 1974)
    NDVI = (NIR - R) / (NIR + R)</li>
<li>Ratio Vegetation Index (Richardson and Wiegand, 1977)
    RVI = R / NIR</li>
<li>Normalized Ratio Vegetation Index (Baret and Guyot, 1991)
    NRVI = (RVI - 1) / (RVI + 1)</li>
<li>Transformed Vegetation Index (Deering et al., 1975)
    TVI = [(NIR - R) / (NIR + R)]^0.5 + 0.5 </li>
<li>Corrected Transformed Ratio Vegetation Index (Perry and Lautenschlager, 1984)
    CTVI = [(NDVI + 0.5) / abs(NDVI + 0.5)] * [abs(NDVI + 0.5)]^0.5</li>
<li>Thiam's Transformed Vegetation Index (Thiam, 1997)
    RVI = [abs(NDVI) + 0.5]^0.5</li>
<li>Soil Adjusted Vegetation Index (Huete, 1988)
    SAVI = [(NIR - R) / (NIR + R)] * (1 + S)</li>
</ul>(NIR = near infrared, R = red, S = soil adjustment factor)

References:
K.R. McCloy (2006): Resource Management Information Systems: Remote Sensing, GIS and Modelling. 2nd Edition, CRC Taylor & Francis, 575pp.

N.G. Silleos, T.K. Alexandridis, I.Z. Gitas & K. Perakis (2006): Vegetation Indices: Advances Made in Biomass Estimation and Vegetation Monitoring in the Last 30 Years, Geocarto International, 21:4, 21-28, <a target="_blank" href="http://dx.doi.org/10.1080/10106040608542399">online</a>.
<hr><h4>Parameters</h4><table border="1" width="100%" valign="top" cellpadding="5" rules="all"><tr><th>Name</th><th>Type</th><th>Identifier</th><th>Description</th><th>Constraints</th></tr>
<tr><th colspan="5">Input</th></tr><tr><td>Red Reflectance </td><td>Grid (input)</td><td>RED</td><td></td><td></td></tr><tr><td>Near Infrared Reflectance </td><td>Grid (input)</td><td>NIR</td><td></td><td></td></tr><tr><th colspan="5">Output</th></tr><tr><td>Difference Vegetation Index (*)</td><td>Grid (optional output)</td><td>DVI</td><td></td><td></td></tr><tr><td>Normalized Difference Vegetation Index (*)</td><td>Grid (optional output)</td><td>NDVI</td><td></td><td></td></tr><tr><td>Ratio Vegetation Index (*)</td><td>Grid (optional output)</td><td>RVI</td><td></td><td></td></tr><tr><td>Normalized Ratio Vegetation Index (*)</td><td>Grid (optional output)</td><td>NRVI</td><td></td><td></td></tr><tr><td>Transformed Vegetation Index (*)</td><td>Grid (optional output)</td><td>TVI</td><td></td><td></td></tr><tr><td>Corrected Transformed Vegetation Index (*)</td><td>Grid (optional output)</td><td>CTVI</td><td></td><td></td></tr><tr><td>Thiam's Transformed Vegetation Index (*)</td><td>Grid (optional output)</td><td>TTVI</td><td></td><td></td></tr><tr><td>Soil Adjusted Vegetation Index (*)</td><td>Grid (optional output)</td><td>SAVI</td><td></td><td></td></tr><tr><th colspan="5">Options</th></tr><tr><td>Soil Adjustment Factor</td><td>Floating point</td><td>SOIL</td><td>Soil adjustment factor for SAVI calculation. Suggested values are 1.0 in case of very low vegetation, 0.5 for intermediate 0.5, and 0.25 for high densities (Silleos et al. 2006).</td><td>Minimum: 0.000000
Maximum: 1.000000
Default: 0.500000</td></tr></table>(*) <i>optional</i>